Saalfrank Corporation is considering two alternatives that are code$-$named M and N$.$ Costs associated with the alternatives are listed below:

$$Alternative MAlternative NSupplies costs$ $50,000$$ $53,000$Assembly costs$ $34,000$$ $34,000$Power costs$ $14,000$$ $21,500$Inspection costs$ $27,000$$ $16,000$

Required:

Which costs are relevant and which are not relevant in the choice between these two alternatives?

What is the differential cost between the two alternatives?